I've heard several times that there are some functions or combinations of those functions which, to an observer, can appear to be something else or be made to do so. How many can you think of?
I've read that SP can appear as N, due to the constantly changing expression modes these two exhibit.
Also, I've read that someone with NT can use these to make a facsimile of F. Quote from INTJ Profile
Although as Ts they do not always have the kind of natural empathy that many Fs do, the Intuitive function can often act as a good substitute by synthesizing the probable meanings behind such things as tone of voice, turn of phrase, and facial expression.